Cloud code validation

cloud/main.js

@@ -96,3 +96,9 @@ Parse.Cloud.define('foo', function(req, res) {
 Parse.Cloud.define('bar', function(req, res) {
   res.error('baz');
 });
+
+Parse.Cloud.define('requiredParameterCheck', function(req, res) {
+  res.success();
+}, function(params) {
+  return params.name;
+});

functions.js

@@ -9,6 +9,13 @@ var router = new PromiseRouter();
 
 function handleCloudFunction(req) {
   if (Parse.Cloud.Functions[req.params.functionName]) {
+    if (Parse.Cloud.Validators[req.params.functionName]) {
+      var result = Parse.Cloud.Validators[req.params.functionName](req.body || {});
+      if (!result) {
+        throw new Parse.Error(Parse.Error.SCRIPT_FAILED, 'Validation failed.');
+      }
+    }
+
     return new Promise(function (resolve, reject) {
       var response = createResponseObject(resolve, reject);
       var request = {

index.js

@@ -124,14 +124,17 @@ function ParseServer(args) {
 
 function addParseCloud() {
   Parse.Cloud.Functions = {};
+  Parse.Cloud.Validators = {};
   Parse.Cloud.Triggers = {
     beforeSave: {},
     beforeDelete: {},
     afterSave: {},
     afterDelete: {}
   };
-  Parse.Cloud.define = function(functionName, handler) {
+
+  Parse.Cloud.define = function(functionName, handler, validationHandler) {
     Parse.Cloud.Functions[functionName] = handler;
+    Parse.Cloud.Validators[functionName] = validationHandler;
   };
   Parse.Cloud.beforeSave = function(parseClass, handler) {
     var className = getClassName(parseClass);

spec/ParseAPI.spec.js

@@ -572,6 +572,42 @@ describe('miscellaneous', function() {
     });
   });
 
+  it('test cloud function parameter validation success', (done) => {
+    // Register a function with validation
+    Parse.Cloud.define('functionWithParameterValidation', (req, res) => {
+      res.success('works');
+    }, (params) => {
+      return params.success === 100;
+    });
+
+    Parse.Cloud.run('functionWithParameterValidation', {"success":100}).then((s) => {
+      delete Parse.Cloud.Functions['functionWithParameterValidation'];
+      done();
+    }, (e) => {
+      fail('Validation should not have failed.');
+      done();
+    });
+  });
+
+  it('test cloud function parameter validation', (done) => {
+    // Register a function with validation
+    Parse.Cloud.define('functionWithParameterValidationFailure', (req, res) => {
+      res.success('noway');
+    }, (params) => {
+      return params.success === 100;
+    });
+
+    Parse.Cloud.run('functionWithParameterValidationFailure', {"success":500}).then((s) => {
+      fail('Validation should not have succeeded');
+      delete Parse.Cloud.Functions['functionWithParameterValidationFailure'];
+      done();
+    }, (e) => {
+      expect(e.code).toEqual(141);
+      expect(e.message).toEqual('Validation failed.');
+      done();
+    });
+  });
+
   it('fails on invalid client key', done => {
     var headers = {
       'Content-Type': 'application/octet-stream',